OZONE-INDUCED MODIFICATION OF STRUCTURAL AND FUNCTIONAL-STATE OF PLASMA-MEMBRANE OF YEAST C-UTILIS

Lipophylic fluorescent probes, pyrene, 1,6-diphenylhexatriene (DPH) an d anthrylvinyl-labeled sphingomielin (ASM) have shown that ozone treat ment increases the hydrophilic nature of the plasma membrane of yeast cells. At the same O-3 dosages, biphase changes of the microviscositie s of annular and bilayer lipids were observed: all the probes displaye d a decrease in the viscosity of microenvironment at low ozone doses a nd its increase at doses of greater than or equal to 4,5 mu mole O-3/m g cell protein. The observed biphase variations in the microviscosity of membrane lipids were correlated with changes in the proton-transloc ating activity of the yeast plasma membrane H+-ATPase which was stimul ated by low O-3 doses.